Resin and method of making the same



Patented Nov. 27, 1934 i UNITED STATES PATENT OFFICE RESIN AND METHOD or MAKING THE SAME Paul F. Schlingman, Schenectady, N. Y., assignor to General Electric Company, acorporation of New York No Drawing. Application April 30, 1929,

' Serial No. 359,433

7 Claims. (01. 260-130) This invention relates to the production of a hyde. In some instances, depending upon the new and improved resin and the method of makamine used, the heat of reaction produced by ing the same. the additionof solution 2 to solution 1 must be When an aromatic amine, such as aniline, is controlled so as not to exceed 40 C. After this 5 caused to react in acid solution with an excess solution has been allowed to stand for one hour of formaldehyde and the solution is neutralized or more, solution No. 3 is added with vigorous by means of an alkali, a product is obtained which stirring until the neutralization is complete. The when dried is an amorphous substance. This resulting precipitate is then freed from electroproduct may be subjected to heat and compreslytes and dried.

l0 sion and thus molded into various shapes with The resin prepared this way may be incoror without fillers. The preparation of such a porated with fillers and a moldable compound product is outlined in the British patent to the is secured which will fiow very easily at tempera- Society of Chemical Industry in Basie, No. 284,589, tures considerably below 150 C. and as low as dated September 13, 1928. 100 C., and at pressures as low as 400-500 pounds 15 The aniline formaldehyde resin, prepared as per square inch, which will be seen is a marked 7 outlined, lacks fiow when molded as in molded improvement over the resin as prepared in accompound practice. The resin so prepared, when cordance with the specification of the British molded at pressures of 2000 pounds per square patent. inch or above, and at temperatures of 150 C. and If an aldehyde content of less than 1.1 mols.

20 above, does not lend itself easily to the formation be employed for each mol. of amine used, the ref of various shapes. Only the most simple shapes, sulting resinous product is the so-called A stage such as fiat strips, blocks. etc.,,can be successfulproduct; that is, additional aldehyde, heat, and 1y made, and this is particularly so when this pressure are required to convert it to the infusible resin is incorporated with various types of fillcondition. A method for preparing such a two- 25 ers. Since moldingmaterials require fillers both stage resin is described in a copending applicafrom an economical and mechanical standpoint tion of Roy H. Kienle, Serial No. 359,423. filed this property of flow is important in a resin used April 30, 1929, and assigned to the same assignee in molding work. as the present invention. In either case, the use I have found that I can produce a ct y of amines having a larger space arrangement in 30 resin of the type referred to which will be a more the molecule than aniline results in more fiexible, easily moldable p d. Iaccomplish this demore plastic, resinous compositions. It is thus sirable end by substituting amino compounds of seen that this process provides a method whereby the aromatic series which constitute a larger aldehyde-amine resins may be rendered more Space arrangement in the molecule than aniline, plastic and flexible, and more easily moldable 35 as fo a p amines having a p y ag than has heretofore been the case. exemplified by benzidine. These resins so prepared may be incorporated In carrying out my inventionIuse compounds, with resins prepared by the ordinary anilinesuch as the di-phenyl amines, benzidine, and the formaldehyde condensation either by dry mixlike, in place of aniline. With these I can use an ing of the finished resin or by mixing the con- 40 aldehyde such as formaldehyde, acetaldehyde and stituents during the process of manufacture. furfural, and prepare the resin. As an example Such practice produces resins exhibiting varying of my inventionIcite the following:-- degrees of plasticity and which can be molded Using benzidine as an example of an amine over a range of temperatures and pressures varyhaving a larger space arrangement in the moleing from C.-200 C., and from little or no .45 cule than aniline, I employ the following forpressure to 3000 pounds per square inch, respec- 100 mula;-- tively.

As an example of this procedure I mention the following, which shows a method of preparation by mixing the constituents during the proc- 1. 1 mol. hydrochloric acid 1 mol. benzidine 2000 cc. water.

" 2. 1.1 mols. aldehyde (formaldehyde) ess manufacture of the resm' 1.0 mol. of aniline is mixed with .005 mol. ib g gi z or Its equwalent benzidine in a suitable amount of water. 1.01

' mols. hydrochloric acid are then added and the Solution No. 2 is added to solution No. 1 at a temperature of the mixture adjusted. 1.11 mols.

55 temperature below the boiling point of the aldeof formaldehyde are now added and the mixture allowed to stand for an hour. Sufficient base or its equivalent is then added to the mixture to effect neutralization, after which the precipitate may be separated, washed, dried, etc.

Furthermore, these higher aromatic amines, which I use in accordance with my invention, may be added to the resin prepared by the specification of the British patent, as such, without using additional acid, aldehyde, or neutralizing base to take care of this added amount. This practice must be followed with care to avoid too great an unbalancing of the reacting constituents. In other words, the addition of the higher amines as such, should notexceedrnore' thana few per cent of the total aniline content.

The following will serve as an exampe of this latter procedure:

1 mol. aniline 1 mol. hydrochloric acid 1 mol. formaldehyde 1 mol. base 3090 cc. water, and

1/ 100 mol. benzidine-are used.

The benzidine is merely added along with the other constituents making up the ordinary resin, without any provision being made for any acid, aldehyde, or neutralizing base to take care of this substance. The resin is then'prepared as outlined above.

As another example of this procedure, the same formula as above is used substituting 1 mol. of o-toluidine for the aniline. 1/190 mol. benzidine is used as above as the plasticizing agent. The resin obtained has marked flow and is easily worked into various shapes.

What I claim as new and desire to secure by Letters Patent of the United States is:--

1. The process of preparing a resin which consists in treating an aromatic amine of the group consisting of benzidine and diphenylamines, with an aldehyde of the group consisting of aldehydes of the lower fatty acid series and furfural, in a solution of non-oxidizing mineral acid which forms an addition product with the amine, precipitating the condensation product with alkali,

and molding said product under heat and pres" sure.

2. The process of preparing a resin which consists in reacting benzidine in non-oxidizing mineral acid solution with formaldehyde, precipitating the condensation product with alkali, and molding said product under heat and pressure.

3. The process of preparing a resin which consists in reacting 1 mol. of benzidine with 1.1 mols.

of formaldehyde-in aqueous medium containing 1 mol. of hydrochloric acid, neutralizing with 1 mol. of alkali to precipitate the condensation product, washing said product free from electrolytes, drying, and molding said dried product with fillers under heat and pressure.

4. The method of forming a plastic, moldable condensation product of the aromatic amineof the group consisting of benzidine and diphenylamines, precipitating the condensation product with alkali, and molding said product under heat and pressure.

6. The neutralized product of the condensation in hydrochloric acid solution of an aromatic amine of the group consisting of benzidine and diphenylamines, and an aldehyde of the group consisting of aldehydes of the lower fatty acid series and furfural, which product is rendered iniuslble under heat and pressure.

7. The neutralized, washed and dried product of the condensation in hydrochloric acid solution of benzid ne and formaldehyde which prodnot is easily molded'under heat and pressure to the infusible state.

PAUL F. SCHLINGMAN. 

